TCT: TAVI Best Bet if Valve Surgery Not an Option

Action Points

Explain to interested patients that among those who were too sick or too old for surgery, replacing malfunctioning aortic valves with bioprostethic ones reduced one-year mortality by 20% compared with standard therapy.

Note that it is unclear whether the results of this trial can be extrapolated to other patient groups at the present time.

WASHINGTON -- In a study of patients who were too sick or too old for surgery, replacing their narrowed, malfunctioning aortic valves with percutaneously implanted bioprostethic ones reduced one-year mortality by 20% compared with standard therapy, researchers reported.

The results mark the first time that a transcatheter aortic valve implantation (TAVI) was evaluated in a randomized trial, and the findings -- 30.7% all-cause mortality at one year versus 50.7% in controls (HR with TAVI 0.55; 95% CI 0.40 to 0.74, P<0.001) -- exceeded even the most optimistic predictions of the investigators.

The team, led by Martin B. Leon, MD, of Columbia University Medical Center/New York-Presbyterian Hospital in New York City, also found that TAVI bested standard therapy, which included medical management and balloon-expandable valvuloplasty, for the combined endpoint of death from any cause or rehospitalization (42.5% for TAVI versus 71.6% for controls, HR 0.46; 95% CI 0.35 to 0.59, P <0.001).

The number needed to treat to prevent one death at one year was five and treating three patients would prevent one death or hospitalization.

The one negative note was the rate of stroke/major bleeding at 30 days -- 12 strokes and 30 major bleeds in the TAVI arm versus three strokes and two major bleeding events in the control group, but by one year the difference in the stroke rate was just 5%, which Leon said "was much better than expected."

The PARTNER trial results were scheduled for initial unveiling here Thursday at the Transcatheter Cardiovascular Therapeutics (TCT) meeting, but in an unusual move, the New England Journal of Medicine upstaged meeting organizers by publishing the results online today.

Asked about lack of synchrony, Leon told MedPage Today that NEJM often publishes papers the day before a scheduled presentation at scientific sessions -- although MedPage Today was unable to find another example -- and said TCT was not going to change it's scheduled late-breaking clinical trial presentation of PARTNER because "there will still be news, other data that are not in the NEJM paper.

One explanation for the "impressive" mortality benefit was that the "patients in the control arm fared much worse than we had predicted. We predicted a one-year mortality of 35%," Michael Mack, MD, of Medical City Dallas and a co-author of the PARTNER (Placement of Aortic Transcatheter Valves) trial, told MedPage Today.

"A 50% mortality was much greater than anticipated, and this tells us much more about the natural history of this disease. It is much more lethal than we thought," he said.

Although the mortality results -- that was the primary endpoint -- were impressive, the improvement in symptoms and function were also compelling and also favored TAVI: at one year just 25.2% of TAVI patients were New York Heart Association class III or IV compared with 58.0% of the controls (P<0.001).

"With patients in their 80s and 90s, the issue is often not survival but quality of life," said Robert Bonow, MD, of Northwestern University in Chicago and a past president of the American Heart Association. Bonow, who was not involved in the study, hailed the results and predicted they would advance the cause of TAVI in the U.S.

The device, the Sapien heart-valve system, is approved and has been in use in Europe for several years.

The average age of patients in PARTNER was 83 and more than 50% were women.

The results reported here and in the journal represent one cohort in the trial -- 358 patients who were judged unsuitable for surgery because a risk score developed by the Society of Thoracic Surgeons (STS) predicted that their risk of dying within 30 days of surgery was 50%.

Another group of high-risk aortic stenosis patients -- those whose chance of dying within 30 days of surgery was closer to 15% -- made up cohort A of the PARTNER trial. Patients in that group were randomized to either a surgical valve repair or to TAVI. Results from that cohort are expected to be reported next spring at the American College of Cardiology meeting.

Richard Shemin, MD, a thoracic surgeon at UCLA, who was not involved in the study, told MedPage Today that those anticipated results represent a truly randomized trial -- comparing TAVI with surgery -- and those results are likely to be more helpful in guiding clinical decisions. "But for patients who are not candidates for surgery, this approach appears to be a good option. It's just that this doesn't tell us that percutaneous implant is the way to go for all patients," Shemin said.

The authors agreed that the study was limited by the exclusion of several important subgroups including patients with coronary stenosis and those with severe peripheral vascular disease. Moreover, assessing the durability and long-term safety of the bioprostethic valve will require more than an one-year follow-up.

While warning that the results cannot be extrapolated to other patient groups, the authors concluded that on the basis of "a rate of death from any cause at one year that was 20 percentage points lower with TAVI than with standard therapy, balloon-expandable TAVI should be the new standard of care for patients with aortic stenosis who are not suitable for surgery."